After United Airlines Flight 12, with 155 passengers and 10 crew, landed in Chicago from Zurich, Switzerland, maintenance workers discovered the slide was missing, the FAA said. The slide was located in a neighborhood near O'Hare, the agency added.
United said no one was injured on the ground. "We immediately contacted the FAA and are working with our team to better understand the circumstances around this matter," United said.
Boeing did not immediately comment.